Making Soap

On this page I'll provide some information and recipes
for making your own soap. I've made three 8 pound batches so far, and
all have turned out very well. Homemade soap is inexpensive, and can be
made to satisfy whatever requirements you have for a good bar of soap --
scents, additives, harness, lather and many other characteristics can be
easily manipulated. Below I'll go through the process. Check out
these books on the subject of making your own soap, they are
excellent:

Susan Miller Cavitch. 1995. The Natural Soap Book: Making
Herbal and Vegetable-Based Soaps. Storey Publishing, Pownal,
Vermont. A multitude of vegetable-oil based recipes, along with
excellent discussions of the chemical process involved in making
soaps. Includes useful tables for formulating your own recipes
based on the chemical composition of various oils, and chapters
on additives, scents and soap characteristics.

Note that making soap involves chemical agents that
generate high temperatures and are very caustic -- proceed * at your
own risk! *

A good scale that can measure weights of at least ten pounds, but
is also accurate enough to weigh individual ounces. Two scales are best
-- one for weights under a pound and one for weights over a pound. Note
that all of the main ingredients in the recipes are measured by weight,
* not * volume. Any exceptions will be noted in the recipe.

Tempered glass container for the lye solution. Mixing the lye crystals
and water generates heat, so the container you use must be able to
tolerate temperatures in excess of 200 degrees F. I use a glass bottle
that once held fruit juice because the juice is sterilized at high
temperatures in the bottle when they produce it. Other good choices
include Pyrex containers, ceramic-coated metal, or stainless steel. The
lye solution will eat away at most other substances. You'll also need to
be able to pour the lye solution in a slow even stream from your container
(without spilling any!!), so make sure this is possible before starting.
I punched two small holes in the lid of the fruit juice bottle.

Spoon made of wood, glass, or stainless steel for stirring solutions.
Lye will react with the wood, but not enough to permanently damage it,
although wood is harder to clean so you may want to consider keeping a
wooden spoon just for this purpose.

Thermometer with a range of at least 70 - 200 degrees F and
graduations down to at least 5 degrees. Two identical thermometers makes
things even easier, but this is not necessary.

Large pot for rendering fats, melting fats and oils and for making
soap. Again, the pot should be either glass, ceramic coated or stainless
steel, because the lye will react with metals like aluminum, cast iron,
copper and will destroy Teflon and other non-stick coatings. I use an
8-quart stainless steel pot).

Mold for the soap. I used the bottom of a 12-pack Hamms carton lined
with a plastic garbage bag. The soap solution will be liquid enough to
seep through even small holes, and the plastic makes removing the soap
from the mold much easier. Make sure the containter you choose is large
enough to hold all the soap, and that you have completely lined it with
plastic.

Tallow - recipes that call for tallow are
referring to rendered beef fat. The advantage of this ingredient is that
it is quite cheap, and if it is in sufficient quantities (like in the
Castille Soap recipe below), the soap you make will actually be cheaper
than buying soap in the store. The disadvantage is that you must first
render the beef fat into tallow -- a disgusting process that takes several
hours. Rendering results in about half as much tallow as you started with
in beef fat, so double the amount of tallow the recipe calls for when you
are buying beef fat. Beef fat can usually be purchased from your butcher.
It make take several days for him or her to accumulate enough fat for
your recipe, so ask in advance. Here are the steps in rendering beef
fat:

Cut the fat into small chunks - the smaller they are the
faster it will render

Pour a few inches of water into a large pot and add a few
tablespoons of salt

The salt solution causes the proteins to settle on the bottom of
the pot, resulting in cleaner tallow

Heat the water on high, and begin adding the fat chunks as you
are cutting them up

Bring the mixture of fat and salt solution to a boil

When the fat begins to rise to the surface, lower the heat to a
low boil

Stir occasionally

After several hours on a low boil, you will have rendered most
of the fat. The longer you cook it the more tallow you will produce,
but I've never gone for more than 4 hours

Strain off the remaining solids (crackle) and keep the liquid
tallow in a large bowl. Throw the solids away. You can get more
tallow if you squeeze the crackle, but this is pretty gross

Refridgerate the bowl of liquid tallow overnight, covered

Upon cooling the fat will form three layers - tallow on top,
greyish fat in the middle, and protein/water on the bottom (which
may have formed a jelly)

Lift the tallow from the bowl and scrape off the greyish fat and
jelly. You should now have an evenly colored, whitish chunk of
tallow. It will keep in the fridge for a few months, and lasts a
long time if frozen in a sealed container

Oils - these are the other major constituants of
soap. Remember to measure them by weight, not volume.

Lye - you need to purchase pure lye (Sodium
hydroxide), which is usually placed next to the Draino in the supermarket.
I've always found lye in the plastic Red Devil cans, but there may be
other brands. Don't use Draino, as it does not contain pure lye.

Water - Any water will do, but distilled water is
best because it eliminates the potential for additional chemical effects
due to the
substances that may be dissolved in regular tap water. If your water is
reasonably pure and doesn't contain a lot of sodium bicarbonate, feel
free to use it. Otherwise, purchase distilled water. Again, you must
measure the water by weight, not volume. One gallon of water weights
approximately eight pounds.

Essential oils - I use a very small amount of
these to give my soap
a hint of aroma. Don't expect the soap to smell exactly like the oil
does because the essential oil will react with the lye just like the
other oils, and the aroma is often slightly changed. I normally use a
half an ounce (liquid measure), but if you unsure, add less rather than
more. A half an ounce in eight pounds of soap is pretty subtle. Essential
oils are added just before pouring into the molds and stirred gently into
the setting soap.

Other ingredients - I put about a third of a cup
of oatmeal in my soap because I like the texture and it is supposed
to give some exfoliating qualities. It, like the essential oils, is
added just before pouring into the molds. Do not cook the oatmeal first
-- put it in raw.

Before I begin describing the procedure, I must once again
warn you that there are very dangerous chemicals involved in making soap.
The lye solution is very caustic, and generates a lot of heat when
forming. Be extremely careful of eyes, skin, children, pets, counters and
anything else that you don't want to become severely burned. If you are
careful, everything will be fine. Proceed at your own risk!

Clean up your work space, put on your safety goggles, gloves and
apron. Close off the room from pets or children, make sure you are sober
and keep on your toes

To weigh the solutions and solids in the recipes use the following
method:

Place the pot or bottle on the scale and note the weight

Add the intended weight from the recipe to the weight of the pot or
bottle

Begin adding the solution or solids to the container on the scale,
stopping when the weight reads the value you calculated in step two. In
other words, the scale should read the weight of the container and the
weight of the solution or solids you added. To add solids, like tallow,
start with large chunks, and as the weight gets close to the final value,
add smaller and smaller pieces.

It is critical that you measure the weights accurately because the
chemical reaction depends on a specific ratio of lye to oils. Too much
lye and there will be lye left in the soap, too little lye and there
will be oils left over.

Fill the container with water up to the specified weight, and then
begin adding lye to the water until you reach the correct final weight.
Don't trust the weight on the bottle of lye. Keep in mind that this
reaction generates head, and the lye solution will be hotter than 200
degrees when you are finished. Also note that the lye solution is very
caustic so handle it with extreme care.

Remove the bottle from the scale with oven mitts (it will be HOT!),
gently stir the solution to dissolve all the lye, and set aside to
cool.

While the lye solution cools, add the fats to your soap pot using
the same weighing method discussed above.

Slowly heat the fats over a low flame.

When most of the fats have dissolved, remove the pot from the heat
and stir until the rest of the solids have dissolved.

Allow the lye solution AND the fat solution to reach the same
temperature, both between 95 and 98 degrees. Heat either if necessary,
or cool in a water bath until both solutions at rest are the same
temperature. If you use heat or a cooling bath, be sure to let the
solutions sit for several minutes away from the heat or cold to
insure you have a good temperature reading.

When the two solutions are at the same temperature, screw the cap
on the lye solution bottle.

Slowly and evenly, pour the lye solution in the fats, while stirring
the solution vigorously (but don't beat the solution, just stir
quickly).

Contiue stirring until the mixture becomes thick enough that drops
of the solution persist on the surface for several seconds (called
tracking). It will be about the consistancy of a thick soup. This may
take as long as an hour and a half and may not even thicken totally after
that period. Do not worry, but stick with it.

After an hour and a half of stirring (or if the solution is thick
enough before that), add the additional ingredients and stir them into
the liquid soap.

Pour the mixture into the mold.

Cover the mold in blankets or place the mold in a styrofoam
container.

Let the soap rest for 24 hours.

After 24 hours the soap will have hardened and can be carefully
removed from the mold.

Once removed, let the giant block of soap sit undisturbed for two
weeks or more until the soap is fully hardened.

If you are making harder soaps (which the two recipes below are),
the large block should be cut into bar-sized pieces once the block is
hard enough -- usually after two days. It is hard enough when you can
cut through it and the bars will hold their shape, even though you can
make depressions in the soap. I use a piece of dental floss to cut my
bars, but you could use a knife as well. Again, let the bars sit for at
least two weeks before using them.

Rinse the new bars in water to remove the powderly soda ash on the
surface.